research

Warming of 2 degrees inevitable over Canada

Halting all emissions of greenhouse gases and aerosols from the Earth’s atmosphere will not immediately stop global warming, says SFU researcher Kirsten Zickfeld, co-author of the first study to reveal this finding.

As a result of past emissions, she says the world’s temperature would continue to rise by about a quarter of a degree for 10 years after achieving zero emissions. Considering that the Earth has already warmed by about one degree since the beginning of the industrial era, this adds up to about 1.3 degrees of global warming. In Canada, however, she predicts a warming of as much as two degrees Celsius, since global warming is amplified at high latitudes.

Zickfeld, an assistant professor of geography, is the co-author of Climate response to zeroed emissions of greenhouse gases and aerosols, published in Nature Climate Change’sonline journal. She wrote the paper with Damon Matthews, an associate professor at Concordia University.

The paper urges the public, governments and industries to wake up to this harsh new reality.

“The only way to stop global warming is to go to zero emissions as soon as possible,” says Zickfeld. “The longer we continue to emit, the higher we will push the amount of warming, possibly crossing dangerous thresholds.

The duo used an earth-system climate model developed at the University of Victoria to study the impact of greenhouse gas and aerosol emissions on the world’s climate. They based the study on emission levels consistent with data from the 2007 report of the Intergovernmental Panel on Climate Change.

The additional warming after emissions are stopped is caused by the removal of aerosols from the atmosphere.

“The widespread presence of aerosols in the Earth’s atmosphere is effectively acting like a solar radiation-blocking blanket right now,” explains Zickfeld. “It’s preventing the Earth’s temperature from responding to the real effects of global warming. But once that aerosol-based blanket is removed, the temperature will rise.”

Zickfeld says that at two degrees of warming, Canada can expect drier summers with increased risk of droughts; wetter winters with increased risks of flooding; melting permafrost in the north, and a further spread of pests such as the pine beetle.